Currently, web application development necessitates accessing an application service provider for data exchange in order to request certain functions. During the application development, an application developer should acquire the internet protocol (IP) address and the port numbers of the application service provider in order to directly access the application service through the IP address and the port numbers. Typically, the application developer can obtain a list containing series IP addresses and the port numbers of various application service providers from an application programming interface (API); and then selects certain IP address and the port numbers of the application service provider providing the necessary functions. As a result, the application developer can access the certain application services to request the necessary functions through the IP addresses and the port numbers acquired from the list in accordance with the need of the web application.
However, the aforementioned approach might encounter problems. For example, whenever a new web application is developed, the application developer would need to request new functions from new application service providers, so new API protocol needs to be learned with cost in order to acquire new IP addresses and port numbers. Meanwhile, the access codes referring to the existing functions need be changed with the new API protocol. In addition, the business information cannot be secured as the IP addresses and the port numbers of the application service provider are exposed to the application service providers.